检索结果-南通市图书馆

Why lowland riparian trees are difficult to use for streamflow reconstruction

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2024年第3期35卷 219-230页

作者： Xiaomei Peng Shengchun Xiao Bao Yang Quanyan Tian vladimir v.Shishov Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000People's Republic of China School of Geography and Ocean Science Nanjing UniversityNanjing 210023People's Republic of China Institute of Fundamental Biology and Biotechnology Siberian Federal UniversityKrasnoyarskRussia 660041

Existing streamflow reconstructions based on tree-ring analysis mostly rely on species from upland,mainly montane areas,while lowland species(generally plain)areas are rarely *** limits the understanding of streamflow change history in the lowlands,which is an important basis for water resource *** study focused on Populus euphratica stands located along the main stream,eastern and western tributaries in the lower reaches of the Heihe River basin(HRb),in arid northwestern *** investigated how streamflow regulation interferes with ripar-ian trees in lowlands when they used for streamflow ***-ring width chronologies were developed and analyzed in conjunction with meteorological and hydrologic observation *** results show streamflow regulation leads in sharp fluctuations in the streamflow allocation between the eastern tributaries and western *** resulted in instability of the correlation between streamflow at the two tributaries and at the Zhengyixia hydrologic station,with corresponding fluctuations in radial growth of poplar trees on the banks of the two tributaries and at the *** regulation altered the natural patterns of seasonal streamflow below the station,changing the time window of poplar *** study provides useful insight into tree-ring width based streamflow reconstruction in the lowlands.

关键词： Tree-ring width-Dendrochronology Populus euphratica The Ejina Oasis Streamflow

Effect of the anionic composition of sulfolane based electrolytes on the performances of lithium-sulfur batteries

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第8期95卷 231-240,I0005页

作者： Elena v.Karaseva Elena v.Kuzmina Bo-Quan Li Qiang Zhang vladimir S.Kolosnitsyn Ufa Institute of Chemistry of the Ufa Federal Research Centre of the Russian Academy of Science 71Prospect OktyabryaUfa 450054BashkortostanRussia Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China

In lithium-sulfur batteries,cell design,specifically electrolyte design,has a key impact on the battery *** effect of lithium salt anion donor number(DN)(DN[PF_(6)]^(-)=2.5,DN[N(SO_(2)CF_(3))_(2)]^(-)=5.4,DN[ClO_(4)]^(-)=8.4,DN[SO_(3)CF_(3)]^(-)=16.9,and DN[NO_(3)]^(-)=21.1)on the patterns of lithium-sulfur batteries and lithium metal electrode performances with sulfola ne-based electrolytes is *** increase in DN of lithium salt anions leads to an increase in the depth and rate of electrochemical reduction of sulfur and long-chain lithium polysulfides and to a decrease in those for medium-and short-chain lithium *** of lithium salt anions has weak effect on the discharge capacity of lithium-sulfur batteries and the Coulomb efficiency during cycling,with the exception of LiSO_(3)CF_(3)and LiNO_(3).An increase in DN of lithium salt anions leads to an increase in the cycling duration of lithium metal anodes and to a decrease in the presence of lithium *** sulfolane solutions of LiNO_(3)and LiSO_(3)CF_(3),lithium polysulfides do not affect the cycling duration of lithium metal anodes.

关键词： Donor number Lithium salt Sulfolane Lithium polysulfide Electrolyte Lithium-sulfur battery Lithium metal electrode

Selection of shaped charges parameters for producing aluminum particles with velocities in the range of 2.5-16 km/s

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第8期38卷 126-135页

作者： vladimir I.Kolpakov Sergey v.Fedorov Ekaterina P.vinogradova Irina A.Bolotina Bauman Moscow State Technical University Moscow 105005Russia

Testing rocket and space technology objects in ground conditions for resistance to the impact of meteoroids and fragments of space debris can be carried out using shaped charges. To substantiate the design parameters of shaped charges that ensure the formation of aluminum particles in a wide velocity range(from 2.5 to 16 km/s), numerical modeling of the formation process was carried out within the framework of a two-dimensional axisymmetric problem of continuum mechanics using three different computing codes to increase the reliability of the results. The calculations consider shaped charges with a diameter of 20-100 mm with aluminum liners of various shapes. It is shown that the formation of particles with velocities close to the lower limit of the considered range is ensured by gently sloping segmental liners of degressive thickness. To form higher-velocity particles with velocities over 5 km/s, it is proposed to use combined liners, the jet-forming part of which has the shape of a hemisphere of constant thickness or the shape of a semi-ellipsoid or semi-superellipsoid of rotation of degressive thickness.

关键词： Space debris Meteoric impact Explosion Shaped charge High-velocity aluminum element Segmental liner Combined liner Numerical simulation

Inversion of walkaway vSP data in the presence of lateral velocity heterogeneity

在线全文

学校读者我要写书评

暂无评论

Energy Geoscience 2024年第2期5卷 304-313页

作者： vladimir Grechka Ilya Tsvankin Pedro Contreras CWP Department of GeophysicsColorado School of MinesGoldenCO80401USA PDvSA-INTEvEP Apartado 76343Caracas1070AVenezuela Borehole Seismic LLC USA Department of Physics ULAVenezuela

Multi-azimuth walkaway vertical seismic profiling is an established technique for the estimation of in situ slowness surfaces and inferring anisotropy ***,this technique requires the assumption of lateral homogeneity,which makes the horizontal slowness components at depths of downhole receivers equal to those measured at the *** violations of this assumption,such as lateral heterogeneity or nonzero dip of intermediate interfaces,lead to distortions in reconstructed slowness surfaces and,consequently,to errors in estimated anisotropic *** this work,we relax the assumption of lateral homogeneity and discuss how to correct vertical seismic profile data for weak lateral *** describe a procedure of downward continuation of recorded traveltimes that accounts for the presence of both vertical inhomogeneity and weak lateral heterogeneity,which produces correct slowness surfaces at depths of downhole receivers,noticing that sufficiently dense receiver coverage along a borehole is required to separate influences of vertical and lateral heterogeneity on measured traveltimes and obtain accurate estimates of the slowness *** the slowness surfaces are found and a desired type of anisotropic model to be inverted is selected,the corresponding anisotropic parameters,providing the best fit to the estimated slownesses,can be *** invert the slowness surfaces of P-waves for parameters of the simplest anisotropic model describing dipping fractures(transversely isotropic medium with a tilted symmetry axis).Five parameters of this model,namely,the P-wave velocity v0 in the direction of the symmetry axis,Thomsen's anisotropic coefficients e and d,the tilt n,and the azimuth b of the symmetry axis,can be estimated in a stable manner when maximum source offset is greater than half of receiver depth.

关键词： Walkaway vertical seismic profile Lateral velocity heterogeneity Anisotropic parameter estimation vertical inhomogeneity

Elucidating elusive quaternary selenide EuCeCuSe3:Synthesis,crystal structure,properties and theoretical studies

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第1期42卷 163-171,I0006页

作者： Maxim v.Grigoriev Anna v.Ruseikina Maxim S.Molokeev vladimir A.Chernyshev Aleksandr S.Aleksandrovsky Alexander S.Krylov Svetlana N.Krylova Nikolai P.Shestakov Dmitriy A.velikanov Alexander A.Garmonov Alexey v.Matigorov Evgeny A.Ostapchuk Thomas Schleid Damir A.Safin Laboratory of Theory and Optimization of Chemical and Technological Processes University of TyumenVolodarskogo Str.6625003TyumenRussian Federation Kirensky Institute of Physics Federal Research Center KSC SB RASAkademgorodok 50 Bld.38660036KrasnoyarskRussian Federation Department of Physics Far Eastern State Transport UniversitySerysheva Str.47680021KrasnoyarskRussian Federation Institute of Natural Sciences and Mathematics Ural Federal University Named After the First President of Russia B.N.YeltsinMira Str.19620002EkaterinburgRussian Federation Department of Photonics and Laser Technology Siberian Federal UniversitySvobodnii Ave.79660079KrasnoyarskRussian Federation Institute of Physics and Technology University of TyumenVolodarskogo Str.6625003 TyumenRussian Federation Institute for Inorganic Chemistry University of StuttgartPfaffenwaldring 55D-70569StuttgartGermany Scientific and Educational and Innovation Center for Chemical and Pharmaceutical Technologies Ural Federal University named after the First President of Russia B.N.YeltsinMira Str.19620002 EkaterinburgRussian Federation University of Tyumen Volodarskogo Str.6625003TyumenRussian Federation

We report on the novel heterometallic quaternary selenide EuCeCuSe3,the fabrication of which has been a challenge until this *** structure of the reported selenide was elucidated from the powder X-ray diffraction data,which revealed the formation of EuCeCuSe3with excellent yield(96.7%)accompanied with a minor fraction of CeSe2(3.3%),and was best solved in orthorhombic space group Pnma with the BaLaCuS3structural ***,the crystal structure of the title compound completes the row of the heterometallic quaternary selenides EuRECuSe3(RE=La,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Y),of which the cerium-based derivative exclusively belongs to the BaLaCuS3structural *** distortion of the CuSe4polyhedron was compared for the whole series of EuRECuSe3compounds using theτ4-descriptor for four coordinated ions,which revealed the highest degree of distortion for the Ce3+-containing selenide,followed by the La3+-based ***,the crystallographic and geometrical parameters of the reported selenide were discussed in comparison to the Ce3+-based sulfides SrCeCuS3and *** initio calculations of the crystal structure,a phonon spectrum and elastic constants for the crystal of EuCeCuSe3were also *** types and wavenumbers of fundame ntal modes were determined and the involvement of ions participating in the phonon modes was *** experimental IR spectrum of the reported selenide was interpreted and found to be in agreement with the calculated *** experimental direct band gap of EuCeCuSe3was measured to be 1.36 ev that is consistent with the concept of its origin due to interband transitions between orbitals emerging mainly from 4f(valence band)and 5d(conduction band)levels of the Eu2+*** dependence of the Young’s modulus on the direction demonstrates the anisotropy of the elastic properties,while the vickers hardness for EuCeCuSe3was calculated to be 5.2 ***,the title compound is paramagnetic above 4 K.

关键词： Quaternary selenide Synthesis Crystal structure Ab initio calculations Magnetic measurements Spectroscopy

ChatGPT: Application in Chemistry Education and Challenges

在线全文

学校读者我要写书评

暂无评论

Journal of Computer and Communications 2024年第3期12卷 196-206页

作者： vladimir L. Kodkin Ekaterina v. Artem’eva Power Engineering Faculty South Ural State University Chelyabinsk Russia Department of Chemistry Institute of Natural Sciences South Ural State University Chelyabinsk Russia

The paper discusses the advancements and applications of neural networks, specifically ChatGPT, in various fields, including chemistry education and research. It examines the benefits of AI and ChatGPT, such as their ability to process and analyze large amounts of data, create personalized training systems, and offer problem-solving recommendations. The paper delves into practical applications, showcasing how ChatGPT can be utilised to augment chemistry learning. It provides examples of using ChatGPT for creating tests, generating multiple-choice questions, and studying chemistry in general. Concerns are voiced about the ethical and societal impact of AI development. In conclusion, it explores the exciting potential of AI to tackle challenges that may exceed human capabilities alone, paving the way for further exploration and collaboration between humans and intelligent machines.

关键词： ChatGPT 3.5 Artificial Intelligence AI for Education Computer-Based Learning

Outcomes of long-acting injectable antipsychotics use in pregnancy:A literature review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Psychiatry 2024年第4期14卷 582-599页

作者： Ana v Pejčić Srdjan M Stefanović MilošN Milosavljević vladimir S Janjić Marko M Folić Nevena D Folić Jovana Z Milosavljević Department of Pharmacology and Toxicology Faculty of Medical SciencesUniversity of KragujevacKragujevac 34000Serbia Department of Pharmacy Faculty of Medical SciencesUniversity of KragujevacKragujevac 34000Serbia Department of Clinical Pharmacology University Clinical Center KragujevacKragujevac 34000Serbia Department of Psychiatry Faculty of Medical SciencesUniversity of KragujevacKragujevac 34000Serbia Clinic for Psychiatry University Clinical Center KragujevacKragujevac 34000Serbia Center for Pharmaceutical and Pharmacological Research Faculty of Medical SciencesUniversity of KragujevacKragujevac 34000Serbia Department of Pediatrics Faculty of Medical SciencesUniversity of KragujevacKragujevac 34000Serbia Pediatric Clinic University Clinical Center KragujevacKragujevac 34000Serbia Department of Anatomy Faculty of Medical SciencesUniversity of KragujevacKragujevac 34000Serbia

BACKGROUND Women with a history of serious psychotic disorders are at increased risk of disease relapse during ***-acting injectable(LAI)antipsychotics have been widely used to improve adherence and prevent relapse in patients with various severe psychotic disorders,but there is a lack of high-quality data from previous research on the safety of LAI antipsychotics during *** To summarize relevant data on maternal,pregnancy,neonatal,and developmental outcomes from published cases of LAI antipsychotic use in *** A literature search was performed through November 11,2023,using three online databases:PubMed/MEDLINE,Scopus,and Web of *** reports or case series that reported information about the outcomes of pregnancy in women who used LAI antipsychotics at any point in pregnancy,with available full texts,were *** statistics,narrative summation,and tabulation of the extracted data were *** A total of 19 publications satisfied the inclusion criteria:3 case series,15 case reports,and 1 conference *** reported the outcomes of LAI antipsychotic use in 74 women and 77 *** use of secondgeneration LAI antipsychotics was reported in the majority(n=47;61.0%)of ***-generation LAI antipsychotics were administered during 30 pregnancies(39.0%).Most of the women(approximately 64%)had either satisfactory control of symptoms or no information about relapse,while approximately 12%of them had developed gestational diabetes mellitus.A minority of cases reported adverse outcomes such as stillbirth,spontaneous abortion,preterm birth,low birth weight,congenital anomalies,and neurological manifestations in ***,there were no reports of negative long-term developmental *** Currently available data seem reassuring,but further well-designed studies are required to properly evaluate the risks and benefits of LAI antipsychotic use during pregnancy.

关键词： Antipsychotic agents Long-acting injectable Pregnancy Outcome Review

Superior piezoelectric performance with high operating temperature in bismuth ferrite-based ternary ceramics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第2期169卷 172-181页

作者： Yunyao Huang Leiyang Zhang Ruiyi Jing Yang Yang vladimir Shur Xiaoyong Wei Li Jin Electronic Materials Research Laboratory Key Laboratory of the Ministry of EducationSchool of Electronic Science and EngineeringXi’an Jiaotong UniversityXi’an 710049China Faculty of Materials and Manufacturing Key Laboratory of Advanced Functional MaterialsEducation Ministry of ChinaBeijing University of TechnologyBeijing 100124China School of Natural Sciences and Mathematics Ural Federal UniversityEkaterinburg620000Russia

Due to the thermal depolarization effect,adequate piezoelectric performance with high operating temperature is regarded to be challenging to accomplish concurrently in piezoceramics for applications in specific piezoelectric *** this work,we synthesized(0.8−x)BiFeO_(3)-x PbTi_(3)-0.2Ba(Zr_(0.25)Ti_(0.75))O_(3)(abbreviated as BFO-x PT-BZT)ternary solid solutions with 0.15≤x≤0.30 by conventional solid-state reaction *** MPB composition with a coexisting state of rhombohedral-tetragonal phases exhibits enhanced electromechanical properties,including Curie temperature of 380℃,large-signal equivalent piezoelectric coefficient d^(∗)_(33)of 395 pm v^(-1),small-signal piezoelectric coefficient d_(33)of 302 pC N^(-1),and electromechanical coupling factor k_(p)of 50.2%,which is comparable to commercial PZT-5A ceramics,indicating potential in high-temperature ***,in-situ X-ray diffraction(XRD)and piezoelectric force microscopic(PFM)techniques demonstrate that multiphase coexistence and complex nanodomains promote piezoelectric response via *** x=0.24 composition exhibits the highest in-situ d_(33)of 577 pC N^(-1)and good temperature stability in 30−280℃,indicating that BZT-modified BFO-PT ceramics are promising candidates for high-temperature piezoelectric devices.

关键词： High-temperature piezoelectrics Morphotropic phase boundary In-situ technique Domain structure BFO

Pulsed THz radiation under ultrafast optical discharge of vacuum photodiode

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Optoelectronics 2024年第2期 100-113页

作者： Aleksandr A.Ushakov Kseniia A.Mamaeva Leonid v.Seleznev Georgy E.Rizaev vladimir Bukin Timophey v.Dolmatov Pavel A.Chizhov vladimir Bagdasarov Sergey v.Garnov Prokhorov General Physics Institute of the Russian Academy of Sciences Physical Institute Russian Academy of Sciences Moscow Institute of Physics and Technology Russian Institute for Scientific and Technical Information

In this paper, we first present an experimental demonstration of terahertz radiation pulse generation with energy up to 5 pJ under the electron emission during ultrafast optical discharge of a vacuum photodiode. We use a femtosecond optical excitation of metallic copper photocathode for the generation of ultrashort electron bunch and up to 45 kv/cm external electric field for the photo-emitted electron acceleration. Measurements of terahertz pulses energy as a function of emitted charge density, incidence angle of optical radiation and applied electric field have been provided. Spectral and polarization characteristics of generated terahertz pulses have also been studied. The proposed semi-analytical model and simulations in COMSOL Multiphysics prove the experimental data and allow for the optimization of experimental conditions aimed at flexible control of radiation parameters.

关键词：